NFL Combine 2014: Monday's studs and duds

Defensive linemen and linebackers took center stage at Lucas Oil Stadium today as on-field workouts continued at the NFL Scouting Combine in Indianapolis. The depth of this draft class, which has been touted by NFL executives and draftniks alike ever since a record 102 underclassmen entered the process, was on full display. Here's a look at some of today's top performers, along with a few prospects who likely didn't help their draft stock.

Studs

Jadeveon Clowney, DE, South Carolina

On Sunday, Auburn defensive end Dee Ford knocked Clowney as an overrated physical specimen who lacks the technique and intangibles needed to be a great pro. But while proper technique can be taught, insane athletic ability can't -- and Clowney's performance today was enough to make NFL talent evaluators giddy. The 6-foot-5, 266-pound freak of nature ran the 40-yard dash in 4.53 seconds to lead all defensive linemen, and finished second with a vertical leap of 37.5 inches and a broad jump of 10 feet, four inches. His time in the 40 was faster than every quarterback and all but 13 running backs who attended the combine this year. Questions about Clowney's work ethic will linger up until draft day, but NFL teams will happily gamble on talent like this. After today, don't be surprised if the Houston Texans roll the dice with the No. 1 overall pick.

Donald, the Outland Trophy winner, put on a show for NFL scouts. His measurables weren't as eye-popping as Clowney's, but they were every bit as impressive for a 285-pound defensive tackle. One day after finish second among all defensive linemen with 35 repetitions on the bench press, Donald turned in the fourth-best time in the 3-cone drill (7.11 seconds), the fifth-best time in the 40 (4.68) and flashed a 32-inch vertical leap. He also showed explosiveness and impressive agility in the on-field drills, likely rising to the top of a very strong crop of interior linemen that also includes Florida State's Timmy Jernigan and Minnesota's Ra'Shede Hageman.

Howard Jones, DE/OLB, Shepherd

The Mountain East Conference isn't the first place you'd look for an NFL-caliber player, but Jones certainly looks like he has all the tools to make a living on Sundays. The 6-foot-2, 235-pound defensive end posted a vertical leap of 40.5 inches -- tops among all defensive linemen by a long shot and the fourth-best mark overall at the combine -- and his broad jump of 10 feet, four inches was tied with Clowney for second among DLs. Jones projects more as a rush linebacker in a 3-4 defense than as a 4-3 defensive end, and his time of 4.6-seconds in the 40 suggests he has more than enough speed to come off the edge. The level of competition he faced at Division II Shepherd University is a real concern, but Jones really helped himself with today's performance and his upside could make him a mid-round bargain on draft day.

Duds

Michael Sam, DE, Missouri

Sam is poised to become the first openly gay player in the NFL, and the league seems ready to welcome him with open arms. But, come draft day, there's bound to be hesitation among general managers when it comes to selecting him. Sam needed to give NFL executives a reason to spend a high draft pick on him despite the media scrutiny it will bring, and today's performance didn't do much to head off a potential draft-day slide. The SEC Defensive Player of the Year is regarded as a "tweener," and he displayed neither the strength to set the edge as a defensive end (only 17 reps in the bench press) nor the athleticism to drop into coverage as an outside linebacker. Sam's measurables -- which included a 4.91 in the 40 and a 25.5-inch vertical -- were pedestrian compared to the top players at his position. Rather than improve his stock, Sam simply reinforced the book on him as an undersized defensive end destined for a situational role in the NFL.

So, while the competition was running a blazing-fast 40, the only thing Ford ran was his mouth. If Ford hoped to close the gap between them today, he had to be disappointed with the outcome.

C.J. Mosley, LB, Alabama

Mosley is a first-round lock, but he's still jockeying with Buffalo's Khalil Mack and UCLA's Anthony Barr to be the first linebacker off the board. He didn't do much to improve his stock today.

After passing on the bench press yesterday, Mosley was unable to run the 40 today because of an IT band injury. His performances in the vertical jump (35 inches) and broad jump (9 feet, 10 inches) were solid, but paled in comparison to the numbers posted by outside linebackers Mack and Ohio State's Ryan Shazier.

While Mosley is still sure to be the first inside linebacker taken in the draft, his hopes of pushing into the top 10 -- perhaps going as high as No. 8 to the Vikings or No. 9 to the Bills -- may now depend solely on his pro day performance.